1. Field of the Invention
The present invention relates to a semiconductor device having a positive side of a power supply voltage set as a common potential.
2. Description of the Related Art
Generally, in fabricating an IC chip including a CMOS circuit, a P type semiconductor substrate is used. In the case of using a P type semiconductor substrate, the substrate potential is set to ground potential, and various types of circuits may be realized with the substrate potential being set as the common potential.
FIG. 1 is a diagram illustrating operations of a semiconductor device according to one example.
As is shown in this drawing, in a semiconductor device using a P type semiconductor device substrate, the ground potential GND becomes the reference voltage, and constant voltages such as VDD1, VDD2, Vout1, and Vout2 may be generated based on the ground voltage GND.
In a semiconductor device using an N type semiconductor substrate, the positive side potential +VDD of the power supply voltage becomes the reference potential.
Since the positive side potential +VDD of the power supply voltage is used as the reference voltage in a semiconductor device using an N type semiconductor substrate, when power is generated internally, the voltage of the power is regulated based on the positive side potential of the power supply voltage, and thereby the generated voltage may not be easily used externally.